Big bird: A flock of starlings flies in formation in the sky above Shapwick Heath National Nature Reserve in Somerset

At first glance it looks like a huge bird travelling across the sky.But this is, in fact, a flock of starlings flying in formation at a Somerset nature reserve. The 'fantastic', not to mention appropriate, shape came about due to the threat of a nearby Peregrine Falcon.Once the flock had spotted the predator, it quickly grouped together and inadvertently mimicked the appearance of a giant bird.When a hungry predator hovers nearby, the birds must converge, flocking together, in an attempt to confuse the hunter, whether it be a sparrowhawk, buzzard or Peregrine Falcons.

'Fantastic': The appropriate shape came about due to the threat of a nearby Peregrine Falcon

These incredible pictures were taken by an amateur photographer at Shapwick Heath National Nature Reserve.Rob Wolstenholme had travelled to the beauty spot specifically to shoot starlings as the area is well known for them.The 51-year-old, himself the manager of a nature reserve in the Cotswolds, said: 'Normally starlings fly in loose and dispersed flocks. But with the Peregrine Falcon circling around them they bunched together and coordinated and acted as one.'I suppose it is some kind of predatory avoidance strategy, because it will make it more difficult for the falcon to pick out one starling.'

Sky at night: Shapwick Heath National Nature Reserve is well known for its starling population

The mass of birds remained in formation for about 15 minutes until the falcon ceased its pursuit and the starlings scattered.Mr Wolstenholme, from Great Somerford, Wiltshire, added: 'I only realised how good the picture was when I looked back at it.'I was just trying to compose a shot without any branches sticking out in the corner, then I found I had got that.'I've never seen anything like it before - it's fantastic.'Scientists recently discovered the secret behind starlings' amazing spatial awareness.

Amateur photographer Rob Wolstenholme (left) had travelled to the beauty spot specifically to shoot starlings. The formation came about due to the presence of a Peregrine Falcon (right)

When they flock together, each starling tracks seven other birds - irrespective of distance - which produces the group's aerial ballet.Eventually, in late spring, birds pair off and look for suitable nesting grounds.They will not regroup until September, when their amazing daily display will begin again.